Improvement in hot-air furnaces



w. B. GEDDE'S.

Improvement in Hot-Air Furnaces.

Patented June 13, 1871.

Earma- .274 numumnmunm :0 it x I asses/1:3 mam-s] i from the dome.

WILLIAM B. GEDDES, OF ROCHESTER, NEW YORK.

IMPROVEMENT IN HOT-AIR FURNACES.

Specification forming part of Letters Patent No. 115,841, dated June 13,1871.

To all whom it may concern:

Be it known that I, WILLIAM B. Gnnnns, of the city of Rochester, countyof Monroe and State of New York, have invented a certain new and usefulImprovement in Furnaces and Stoves, of which the following isaspecification:

Nature of the Invention.

My invention consists in the construction of a heating furnace or stove,as hereinafter described, whereby the air is passed from the exteriorheatingchamber inward through the thimbles of a hollow drum to an innerchamber, and thence to the douie, where it is distributed, the said drumforming within itswalls the flue-space for the passage of the productsof combustion. It also consists in an arrangement for introducing steam,both to the fire to aid the combustion, and to the heated air, forimpregnating the same with moisture; and it furthermore consists in thespecial arran gement of parts,as hereinafter described.

General Description.

In the drawing, Figure 1 is a central vertical section ofmyimprovedfurnace; Fig. 2, a crosssection in the plane of line a: m, Fig. 1; Fig.3, a similar section in the plane of line 3 3 Fig. 1; Fig. 4, aperspective view of the water-pan and connecting parts detached.

This furnace may be made either portable or stationary, as may bedesirable. The drawing shows the portable form.

A represents the outer cylinder, which incloses the hot-air chamber B. 0represents the dome, from which the hot air is drawn to difi'erentapartments by exit-pipes D D D. A diaphragm, a, separates the hot-airchamber This diaphragm is provided with openings or passages b b b,whose object will presently be described. E represents the ash-pit; F,the grate; and G, the firepot. These parts are of ordinary construction.H represents the heating-drum or sheet, which v rests upon the top ofthe fire-pot and forms a continuation of the fire-place. It is madeenlarged, as shown, so as to get a greater heating capacity, and theconnection with the firepot is made by a funnel-shaped rim, 0. The drumis constructed of separate rings resting one on top of another, and withseparate walls d d, which leave a clear flue-space between for thepassage of the products of combustion. Each ring of the drum has aseries of radial thimbles or pipes, K, cast therein, opening from theouter chamber B to the inner one, C, which is simply the interior of thedrum, and communicates with domechamber 0. These several series ofthimbles alternate in position, so as to break joint vertically, bywhich means the heat-currents from the combustion are broken in theircourse and equally distributed through the whole flue-space. The top ofthe drum surrounding the heat-chamber is made arching or convex on top,as shown at f. From one side of this arch rises the smoke-pipe L, whichpasses out through the dome, and then is carried to the chimney in anydesired manner. With the smoke-pipe is connected two right-angled armsof pipe, L L, situated within the dome, but opening outside. In the openends of these arms are situated thimbles M M, having closed heads h h,which, when closed up tight, stop the arms, so as to insure an activedraught. 'When drawn out to a suitable degree, register-holes i t in thethimbles are exposed, which allow a passage of cold air to deaden thedraught. When the thimbles are removed entirely, they allow a freepassage of a poker or other device inward to clear the flues of ashes,which are thus thrown down into the flue-space of the drum, which isself-clearing. This arrangement of the pipe-arms L L is for governingthe draught and clearing the pipe of ashes. Directly over the fire-potand opening into the drum-chamber C is situated a cone, N. This cone ishollow and open at its bottom to allow the entrance of heat from thetire, which, passing inward and circling around, finally returns andpasses up the flue-space of the drum. The sides of this cone within thedrum-chamber are made in concave segments 70 k, which come just oppositethe lower thimbles K K, and thus serve to deflect the air-currentsupward in a straight line to the top, where they become thoroughlycommingled and rise in an equalized state to the dome-chamber above.

One great merit of my invention consists in the before-describedconstruction of the drum, whereby the cold air is made to pass throughthe thimbles K K into an interior chamber. The air becomes partiallyheated in the outer chamber B -in fact, as much so as it does inordinary furnaces, which depend entirely upon the radiation outwardlyfrom a common cylinder. This partially-heated air then passes inwardthrough thimbles K, where it receives the benefit from the heat passingthrough the flue-space of the drum and encircling the thimbles. On itsdischarge inward it receives the radiation from the inner walls of thedrum, and also from the central cone; and in rising it surrounds thearch f and the smoke-pipe which is inclosed in the dome.

By this arrangement I can attain a much higher degree of heat with agiven capacity of furnace than in ordinary devices which simply dependupon the radiation of an outer cylinder, or an outer cylinder with asystem of pipes; since, in my case, the radiating surfaces are all inlarge bodies, and the air, in passing over th emin the indirect circuitdescribed, extracts the maximum of heat in the shortest time. The actionof the air is so rapid that it cannot become burned, as it would ifmoving in small and obstructed bodies.

I am aware of no heating-furnace in which the air is thus passed inwardthrough a tubular drum to an inner chamber intermediate with the outerchamber or dome. There is, in this connection, an advantage in theemployment of the passages 11 b from the outer chamber to the dome,which allow the escape upward of any excess of the heated air in thechamber B, thus relieving it, and, at the same time, tempering theheated air in the upper chamber by reason of its lower grade of heat.This allows a constant movement of the air, and prevents any deadeningthat might occur in the upper part of the chamber B were the sameclosed.

I locate in the front part of chamber B, surrounding the fire-pot, awater-basin or tank, 1?, which constantly contains a body of water,which is evaporated or raised in the form of steam. Below this basin ismade a passage, m, through the top of the ash-pit near the grate. Thispassage is covered by a registerslide,n,whose stem 19 extends out withinreach of the operator. This arrangement accomplishes a double effect,viz., the steam rises to a certain extent through chamber B and thusmoistens the heated air, and a portion is drawn downward through passagem and passes into the fire, thereby assisting in the combustion by aunion of its inflammable gases with the flame.

I am aware that water-basins are common in furnaces simply formoistening the air; but, so far as I am aware, they have never beforebeen combined with a passage and registerslide in proximity, by whichthe excess of steam may be drawn into the fire to assist the burning,being at the same time graduated in its action by the closing, more orless, of the register. The hot air from the chamber B also enterswiththe steam to support the combustion, being much more effective than coldair from the outside.

It will be seen that this same principle of the heating-drum andconnecting parts may be applied to stoves as well as furnaces, in whichcase the drum is surrounded with the outer cylinder A in the samemanner, thereby forming chamber B, which supplies the partially-heatedair to the drum.

Claims.

What I claim as my invention, and desire to secure by Letters Patent,is-

1. The drum H, constructed of a series of rings formed with the walls (1d and pipes 70 7c, in combination with the air-passages I) b, dome O,exit-pipes D, shell-cone N, and fire-pot G, the several parts beingconstructed and arranged to operate as herein set forth.

2. The shell-cone N, dome 0, air-passages b b, stove-pipe L, with arms LL and thimbles M M, arranged and operating in connection with the drumH, composed of the series of rings provided with the walls (1 d, pipesla 70, and drum resting upon the fire-pot G, and forming a continuationof the fire-space, substantially as set forth.

3. The water-basin P, arranged within the front part of the chamber Bsurrounding the fire-pot G, operating in connection with the passage min thetop of the ash-pit E, said opening at being opened and closed bythe slide a and stem 19, as herein shown and described.

WILLIAM B. GEDDES.

Witnesses:

B. F. Oseoon, J. P. BARNES.

